Marcus Gilchrist has been taking reps at strong safety this offseason.

The experiment didn't slow Monday at organized team activities.

The Chargers defensive back worked with the starters opposite Eric Weddle during the first day of OTAs. Gilchrist, who played some safety at Clemson, primarily has been a cornerback since being drafted in 2011.

In three of four spots, San Diego's secondary could have a new starter.

Derek Cox replaces free agent Quentin Jammer at left corner. Shareece Wright worked with the ones Monday on the right side, a spot vacated by Cardinals cornerback Antoine Cason. And then there's Gilchrist, replacing free agent Atari Bigby.

"From a young age, my dad always told me if you're going to play DB, you should play any position," Gilchrist, 24, said. "I've always looked at it from that aspect, being able to be versatile enough to play corner, nickel and safety."

In terms of offseason turnover, the Chargers' offensive line is the only position group that rivals the secondary.

Ex-right tackle Jeromey Clary worked with the starters Monday at right guard. King Dunlap was at left tackle, Chad Rinehart was at left guard and rookie D.J. Fluker played right tackle, leaving center Nick Hardwick as the only Chargers offensive lineman returning to the position in which he started last year.

Here in May, most spots on the depth chart are subject to change. That applies to the line's left side.

The Chargers could add a free agent tackle, moving the versatile Dunlap into a reserve role. Left guard Johnnie Troutman, a 2012 fifth-round pick, worked with the second-team offense Monday and, despite not having Rinehart's experience or familiarity with line coach Joe D'Alessandris, could push for a spot in training camp.

Nuts 'n' Bolts

• Strong safety Brandon Taylor has yet to begin practicing, instead working to the side. He had surgery in January to repair a torn ACL.

• Inside linebacker D.J. Smith, formerly of the Packers, also is coming off an ACL surgery. He and Taylor's availability for the July start of training camp is in question.